\begin{tikzpicture}
    \pgfmathsetmacro{\a}{2}
    \tkzDefPoints{0/0/A, \a/0/B, \a/\a/C, 0/\a/D, 0/\a+\a/E, \a/\a+\a/F}
    \tkzInterLL(D,F)(C,E)  \tkzGetPoint{O}
    \tkzDefTriangle[two angles=45 and 45](D,E)  \tkzGetPoint{G}
    \tkzDefTriangle[two angles=45 and 45](F,C)  \tkzGetPoint{H}

    \tkzDrawPolygon(A,B,C,D)
    \tkzDrawPolygon(D,G,E,O)
    \tkzDrawPolygon(C,H,F,O)
    \tkzDrawSegments[dashed](A,C  B,D  D,E  C,F)
\end{tikzpicture}

